There is a method of collectively cutting out a plurality of thin plates from a workpiece by arranging wire electrodes in parallel by winding one wire electrode between a plurality of guide rollers and applying a voltage and generating a discharge between the wire electrodes and the columnar workpiece.
Moreover, Patent Literature 1 discloses a technology in which a structure, in which an insulator and a slidable contact conductor that is in slidable contact with a wire are alternately laminated, is provided in a power feeding unit for the cutting wires, and the amount of machining per unit time is made substantially equal in each cutting wire by maintaining a high discharge voltage between a cutting wire unit and a workpiece by feeding power individually between the workpiece and the cutting wires via a conductor electrically connected to the power source and the slidable contact conductors.